Set in a world where The Joker is cured of his insanity and homicidal tendencies, The Joker, now known as “Jack,” sets about trying to right his wrongs. First he plans to reconcile with Harley Quinn, and then he’ll try to save the city from the one person who he thinks is truly Gotham City’s greatest villain: Batman!

Public support for Batman dwindles and Gotham City’s 99 percent rally around ex-Joker Jack Napier’s crusade to expose decades of corruption within the GCPD. A proposition inspires new revelations about Harley and The Joker’s past; and as Jack transforms into a hero of the middle class and takes extreme measures to mobilize a revolutionary army of super-villains, Bruce struggles to stay focused on engineering a technological breakthrough to save Alfred.

Lors d'un combat particulièrement violent contre un Batman devenu fou furieux, le Joker ingère un traitement qui le guérit totalement de sa psychose. Devenu sain d'esprit, il décide de se présenter au poste de maire de Gotham et de guérir la cité de son fléau : Batman !